1967 Mk-Ii Moke Wiper Wheelbox Cross Reference

I am working at restoring a 1967 MK-II Moke (UK, 10" wheels). I need to replace the wiper wheelboxes as the mounting threads are badly worn and will no longer hold the retaining nut.

The dilemma: I cannot seem to locate or cross-reference the original wheelboxes. The original wheelboxes are stamped 72814A and have a concave, 27 tooth gear. Various internet searches do not find anything for that part number.

All I seem to find at any of the suppliers are the wheelboxes for the Saloons in either MK-I/MK-II (22 tooth) or MK-III+ (32 tooth).

Does anyone have an old, paper cross reference to a currently available wheelbox or know which of the two available Saloon ones would be the better choice/match?